The invention relates to a fuel injection system for mixture compressing externally ignited internal combustion engines. The type of engine to which this invention especially relates has an injection location in the air induction manifold.
The free flow aperture of the induction tube can be varied by means of an arbitrarily movable throttle element which also displaces the movable part of a fuel metering valve.
Fuel injection systems of this type are employed to obtain an automatic favorable adjustment of fuel-air mixture for all operational conditions of the engine so as to obtain complete combustion of fuel and the highest power or lowest fuel consumption. In addition, the concentration of toxic components in the exhaust gas is sharply reduced or entirely absent. This type of control requires that the fuel quantity be metered out very precisely according to the engine requirements.
In known fuel injection systems of this general type, the air quantity flowing through the induction tube is measured by an air flow rate meter and fuel is metered out proportional to the air quantity separately for each engine cylinder and is injected separately by individual injection valves in the vicinity of each cylinder. An embodiment of this type of fuel injection system is very expensive and complicated.